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Papers by Yeosvany Cabrera

The Journal of Microbiology, Biotechnology and Food Sciences, Apr 1, 2022

Fish and Shellfish Immunology Reports

Journal of microbiology, biotechnology and food sciences

Monoclonal antibodies (mAbs) have become essential analytical tools for biomedical and veterinary... more Monoclonal antibodies (mAbs) have become essential analytical tools for biomedical and veterinary diagnosis and the analytical release of other biomolecules due to their high specificity and reproducibility. The mAbs generated in mice contain murine serum albumin (MSA) as the main potential contaminant; this molecule interferes in a large number of tests in which these mAbs are required. For this reason, the development of analytical methods to identify and quantify MSA traces plays an important role in the quality of purified mAb. In this study, an anti-MSA polyclonal antibody (pAb) was generated in rabbit with titers of 1:2 700 000 and purified by nProtein A affinity chromatography with purity greater than 90%. The purified antibody was conjugated to horseradish peroxidase (HRP) by the m-periodate method with an optimal working dilution of 1:64 000 in direct ELISA. Two applications were evaluated for the analytical release of mAbs: identity test by Western Blot and direct ELISA, a...

Agrociencia Uruguay, 2014

Journal of Immunological Methods, 2022

COVID-19 pandemic poses a serious threat to human health; it has completely disrupted global stab... more COVID-19 pandemic poses a serious threat to human health; it has completely disrupted global stability, making vaccine development an important goal to achieve. Monoclonal antibodies play an important role in subunit vaccines strategies. In this work, nine murine MAbs against the RBD of the SARS-CoV-2 spike protein were obtained by hybridoma technology. Characterization of purified antibodies demonstrated that five of them have affinities in the order of 108 L/mol. Six of the eight MAbs showed specific recognition of different recombinant RBD-S antigens in solution. Studies of the additivity index of anti-RBD antibodies, by using a novel procedure to determine the additivity cut point, showed recognition of at least five different epitopes. The MAbs CBSSRBD-S.11 and CBSSRBD-S.8 revealed significant neutralizing capacity against SARS-CoV-2 in an ACE2-RBD binding inhibition assay (IC50 = 85.5pM and IC50 = 122.7pM, respectively) and in a virus neutralizing test with intact SARS-CoV-2 (VN50 = 0.552 nM and VN50 = 4.854 nM, respectively) when D614G strain was used to infect Vero cells. Also CBSSRBD-S.11 neutralized the SARS-CoV-2 strains Alpha and Beta: VN50 = 0.707 nM and VN50 = 0.132 nM, respectively. The high affinity CBSSRBD-S.8 and CBSSRBD-S.7 recognized different epitopes, so they are suitable for the development of a sandwich ELISA to quantitate RBD-S recombinant antigens in biomanufacturing processes, as well as in pharmacokinetic studies in clinical and preclinical trials.

Revista latinoamericana de microbiología

The Thermus aquaticus DNA Polymerase I (Taq Pol I) gene was cloned into the pOSEX4 plasmid under ... more The Thermus aquaticus DNA Polymerase I (Taq Pol I) gene was cloned into the pOSEX4 plasmid under the osmo-inducible promoter proU and subsequently expressed into the Escherichia coli MKH13 strain. The suitability of the enzyme in polymerase assays was determined in standard 35S dATP incorporation tests and by PCR. The Taq Pol I expression in this system, which is under the control of the osmotic pressure in the growth medium, was analyzed in different media and in different sodium chloride concentrations. A study of the osmolarity effects in the growth of the strain and in Taq Pol I expression shows that an increase in sodium chloride concentration limits the growth. At 0.25 M of NaCl maximum activity was observed; at higher values of osmolarity, we found an unexpected decline of activity. This is the first report of using the pOSEX vector for the expression of an heterologous protein and it is very advantageous to make a regulated, non toxic, simple and cost-effective manner of ind...

Biotecnología Vegetal, 2007

Biotecnología …, 2009

... Raúl Armas 1 , Carlos Hernández 1 , Daymi Abreu 1 , Maylin Pérez 1 , Yeosvany Cabrera 1 , Mer... more ... Raúl Armas 1 , Carlos Hernández 1 , Daymi Abreu 1 , Maylin Pérez 1 , Yeosvany Cabrera 1 , Merardo Pujol 2 , Julio Alfonso-Rubi 1. 1 Center for Genetic Engineering and Biotechnology, CIGB. ... PO Box 83, Sancti Spíritus, Cuba. E-mail: raul.armas@cigb.edu.cu. ...

Biotecnologia Aplicada

in Cuba. Here, we describe the production of transgenic rice plants expressing barley cystatin Hv... more in Cuba. Here, we describe the production of transgenic rice plants expressing barley cystatin HvCPI-1 (Icy1 gene) to explore the potential of this protein for the control of rice water weevil. Rice plants (Oryza sativa L. cv IACuba-28) were transformed via Agrobacterium tumefaciens with a plasmid carrying the Icy1 gene fused to the 35S promoter and the first exon/intron/exon from rice actin-1 gene. From 65 independent transgenic lines, 62 were positive in the PCR-Southern blot analyses. The transgene was correctly translated as indicated by western- and dot-blot assays with level of expression in T1 plants of up to 2% of the total extracted protein. The functional integrity of the protein was confirmed in vitro by a reduction of up to 90% of the cysteine-proteinase activity in the gut of rice water weevils exposed to rice leaf extracts. Moreover, proteins extracted from T2 transgenic rice roots showed a significant inhibition of up to 70% at pH 4.5 and 45% at pH 6.0 of the cathepsi...